1. Field of the Invention
An IV catheter insertion device which shields users from accidental needlestick injury from the catheter insertion needle and which protects patients from venous injury during accurate IV catheter placement.
2. Prior Art
In health care settings cross-infection of incurable blood-borne virus infections, including Hepatitis B Virus (HBV), Hepatitis C Virus (HCV), Human Immunodeficiency Virus (HIV), Human T-cell Leukemia Virus (HTLV), and skin-borne antibiotic-resistant bacterial infections, have made it imperative to offer better devices for giving injections and intravenous infusions into patients safely and efficiently. Intravenous silastic catheters have proven extremely useful in hospital settings because, after proper insertion, they may remain in place in a patient for more than a day with minimal venous irritation; and pose no needlestick hazards to health care workers when removed. However, most silastic catheters commonly used in small veins require IV insertion via a hollow-bore steel needle with a sharp beveled tip which is extremely hazardous to users and bystanders and potentially injurious to veins.
Currently, two types of protective devices are commonly used for inserting IV catheters, i.e. devices not filled with infusion fluid before insertion of the catheter and devices filled before insertion of the catheter over-the-needle. Shields' U.S. Pat. No. 5,007,901 (Apr. 16, 1991) applies to both by disclosing an insertion needle guide which breaks away from the trailing end of the insertion needle, such that the entire needle can be trapped during withdrawal into the puncture-resistant housing of the assemby. However, simple specific means for trapping the insertion needle were not clearly specified.
Subsequently, Shields' U.S. Pat. No. 5,401,250 (Mar. 28, 1995) disclosed the use of a hollow cone to wedge impact the hub of a retracted hollow bore steel needle, such that the beveled tip could be safely shielded inside. Further, Shields' U.S. Pat. No. 5,007,901 (Apr. 16, 1991) specified the use of an elastomeric syringe piston for stabilizing the thrust and retraction of the IV catheter insertion needle. However, use of the trailing recess in said piston for manually controlling forward and backward displacement of the hollow-bore steel needle bevel in relation to the leading taper on an IV catheter was not claimed. This innovation, applicable to catheter insertion devices not filled with infusion fluid before insertion of the catheter, remains unclaimed by other inventors. The innovation may prove useful for preventing venous intimal injury, as well as shearing of the catheter by poorly controlled advancement of the needle bevel inside the catheter during the process of IV insertion.
Among competing devices designed for safe user IV catheter insertion via unfilled insertion assemblies, the Critikon PROTECTIV.TM. and the Becton-Dickinson Insyte.TM. systems are not structurally comparable because the former depends on a latch mechanism which traps a manually retracted inside-the-catheter insertion needle; and the latter depends on a latched spring mechanism which allows no options for gradually retracting or advancing the insertion needle inside the catheter after IV penetration. Neither is in the best interests of patients, because the former is awkward for users to manipulate between the first and third fingers of the dominant hand with the index finger controlling the relative position of the steel insertion needle; and complications have ensued as a result of catheter shearing by the needle bevel. The latter lacks means for finely adjusting the relationship between the insertion hollow-bore needle bevel and the leading taper in the IV catheter.
Among fluid-filled assemblies, B-D/Deseret currently produce a winged infusion set with a telescoping trailing addition which traps a catheter insertion needle with a vented shank. The instant invention differs in that the catheter insertion needle hub is vented amd trapped by wedge impaction inside the trailing end of the IV catheter insertion assembly.